Luminescent amphiphilic 2,6-bis(1-alkylpyrazol-3-yl)pyridyl platinum(II) Complexes: Synthesis, characterization, electrochemical, photophysical, and langmuir-blodgett film formation studies

Abstract

Two series of novel platinum(II) 2, 6-bis(1-alkylpyrazol-3-yl)pyridyl (N5Cn) complexes, [Pt(N5Cn)Cl] [X] (1-9) and [Pt(N5Cn)(C≡CR)][X] (10-13) (X = trifluoromethanesulfonate (OTf) or PF 6; R = C 6H 5, C 6H 4-p-CF 3 and C 6H 4-p-N(C 6H 5) 2), with various chain lengths of the alkyl groups on the nitrogen atom of the pyrazolyl units have been successfully synthesized and characterized. Their electrochemical and photophysical properties have been studied. Some of their molecular structures have also been determined by X-ray crystallography. Two amphiphilic platinum(II) 2, 6-bis(1-tetradecylpyrazol-3-yl)pyridyl (N5C14) complexes, [Pt(N5C14)Cl]PF 6 (7) and [Pt(N5C14)(C≡CC 6H 5)]PF 6 (13), were found to form stable and reproducible Langmuir-Blodgett (LB) films at the air-water interface. The characterization of such LB films has been investigated by the study of their surface pressure-area (π-A) isotherms, UV/ Vis spectroscopy, XRD, X-ray photoelectron spectroscopy (XPS), FTIR, and polarized IR spectroscopy. The luminescence property of 13 in LB films has also been studied. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.